Elecraft › [QRO]

KPA500 with K3 in TUNE mode?

Classic

List

Threaded

12 messages Options

w8fn

KPA500 with K3 in TUNE mode?

I'm busily preparing for my new KPA500 and working out all the station
interface details. One of my antennas uses an SGC SG-235 remote tuner,
which will support the amp's 500W output but must be tuned at lower
power. I currently just hold the K3's TUNE button to generate about 20W
to tune the SG-235. Once the tuner has found and memorized a match at a
given frequency, it only takes a very short burst of low power RF to
reset on QSY, but it really needs to be done at 100W or less. This is no
problem with the barefoot K3 -- I can recall the tune setup with a
couple of dashes from the keyer. This technique would be disastrous
once the KPA500 is online, so I'm clearly going to need a way to
initially transmit at lower power after a band change to wake the tuner
up. I realize I could select the menu option to drop the amp offline
after every band change, but since I need to turn the amp off only with
one of several antennas, this is a lot of ergonomic overhead.

With the K3 and KPA500 integrated and talking via the AUXBUS will the
firmware keep the amp offline when the K3 is in TUNE mode? This would
be really useful for my particular setup, and for anyone who uses a
remote tuner. I've looked over the manual for the KPA500 and it says
nothing about the behavior in this case.

If the amp stays live in TUNE, perhaps a future revision of the firmware
could present a menu item to let the user choose whether or not the amp
will be enabled in TUNE mode.

73...
Randy, W8FN
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

N5GE

Re: KPA500 with K3 in TUNE mode?

Hello Randy,

You should put the Amplifier in standby and let the tuner tune from the K3's
Tune power. That applies to all amplifiers. It doesn't make any difference
what brand of amplifier or what type of tuner you have you have.

The safe way to tune a tuner before applying amplifier power is what I described
above, no matter what it's final output will be.

73,
Tom
Amateur Radio Operator N5GE

On Tue, 10 May 2011 21:49:05 -0500, Randy Farmer <[hidden email]> wrote:

>I'm busily preparing for my new KPA500 and working out all the station
>interface details. One of my antennas uses an SGC SG-235 remote tuner,
>which will support the amp's 500W output but must be tuned at lower
>power. I currently just hold the K3's TUNE button to generate about 20W
>to tune the SG-235. Once the tuner has found and memorized a match at a
>given frequency, it only takes a very short burst of low power RF to
>reset on QSY, but it really needs to be done at 100W or less. This is no
>problem with the barefoot K3 -- I can recall the tune setup with a
>couple of dashes from the keyer. This technique would be disastrous
>once the KPA500 is online, so I'm clearly going to need a way to
>initially transmit at lower power after a band change to wake the tuner
>up. I realize I could select the menu option to drop the amp offline
>after every band change, but since I need to turn the amp off only with
>one of several antennas, this is a lot of ergonomic overhead.
>
>With the K3 and KPA500 integrated and talking via the AUXBUS will the
>firmware keep the amp offline when the K3 is in TUNE mode? This would
>be really useful for my particular setup, and for anyone who uses a
>remote tuner. I've looked over the manual for the KPA500 and it says
>nothing about the behavior in this case.
>
>If the amp stays live in TUNE, perhaps a future revision of the firmware
>could present a menu item to let the user choose whether or not the amp
>will be enabled in TUNE mode.
>
>73...
>Randy, W8FN
>______________________________________________________________
>Elecraft mailing list
>Home: http://mailman.qth.net/mailman/listinfo/elecraft
>Help: http://mailman.qth.net/mmfaq.htm
>Post: mailto:[hidden email]
>
>This list hosted by: http://www.qsl.net
>Please help support this email list: http://www.qsl.net/donate.html

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Amateur Radio Operator N5GE

Phil Salas

Re: KPA500 with K3 in TUNE mode?

In reply to this post by w8fn

The AUXBUS provides one-way communication between the KPA500 and the K3
(KPA500 to K3). So the KPA500 won't know that the K3 is in TUNE mode. The
KPA500 has about 12-13 dB gain, so if the SG235 can take up to 100 watts
without problems, you could set the TUNE mode to output no more than 5-watts
for tuning. Unfortunately the K3 amp-enable output is always active whether
in TUNE mode or normal operating mode (I understand this is hard-wired and
so can't be changed in firmware).

What would be nice is if the K3 would output a signal (Dig Out 0 or Dig Out
1?) that would feed the amp-inhibit input on the KPA500 (pin 11) when you
press TUNE on the K3. Not sure if this is possible, but that would do the
trick.

Phil - AD5X

"I'm busily preparing for my new KPA500 and working out all the station
interface details. One of my antennas uses an SGC SG-235 remote tuner,
which will support the amp's 500W output but must be tuned at lower
power. I currently just hold the K3's TUNE button to generate about 20W
to tune the SG-235. Once the tuner has found and memorized a match at a
given frequency, it only takes a very short burst of low power RF to
reset on QSY, but it really needs to be done at 100W or less. This is no
problem with the barefoot K3 -- I can recall the tune setup with a
couple of dashes from the keyer. This technique would be disastrous
once the KPA500 is online, so I'm clearly going to need a way to
initially transmit at lower power after a band change to wake the tuner
up. I realize I could select the menu option to drop the amp offline
after every band change, but since I need to turn the amp off only with
one of several antennas, this is a lot of ergonomic overhead.

With the K3 and KPA500 integrated and talking via the AUXBUS will the
firmware keep the amp offline when the K3 is in TUNE mode? This would
be really useful for my particular setup, and for anyone who uses a
remote tuner. I've looked over the manual for the KPA500 and it says
nothing about the behavior in this case.

If the amp stays live in TUNE, perhaps a future revision of the firmware
could present a menu item to let the user choose whether or not the amp
will be enabled in TUNE mode.

73...
Randy, W8FN"

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Chuck Shefflette

Re: KPA500 with K3 in TUNE mode?

In reply to this post by w8fn

I see that Phil - AD5X replied along the same lines but I'll toss my $0.02 in. With about 13 dB gain, an input of 1-2 watts would give you 20-40 watts out. I have my TUN PWR set to 2.5w typically so I can get a quick read of an antenna without risking the finals by pressing Tune. If you use that, you should be fine no with your SGC tuner. Just a thought but it does take the extra step of putting the amp in standby out of the picture and requires no hardware or firmware changes anywhere.

73 - Chuck AA3CS

Sent from my iPhone
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

73 - Chuck, AA3CS

Bob Naumann W5OV

Re: KPA500 with K3 in TUNE mode?

In reply to this post by w8fn

While automating this (disable PTT to the amp for the first transmission
after a band change - just like Tokyo Hy-Power does) should be part of the
eventual Elecraft tuner /amp implementation, and not just when in tune mode,
I'm surprised that pressing the "OPER/STBY" button on the front panel of the
KPA500 constitutes "a lot of ergonomic overhead"?

I think of what was "normal" with something like a Drake C-line, MN2000
tuner and L4B amplifier. Now, there's some ergonomic overhead!

Times and perspectives certainly have changed.

73,

Bob W5OV

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Randy Farmer
Sent: Tuesday, May 10, 2011 9:49 PM
To: [hidden email]
Subject: [Elecraft] KPA500 with K3 in TUNE mode?

I'm busily preparing for my new KPA500 and working out all the station
interface details. One of my antennas uses an SGC SG-235 remote tuner,
which will support the amp's 500W output but must be tuned at lower
power. I currently just hold the K3's TUNE button to generate about 20W
to tune the SG-235. Once the tuner has found and memorized a match at a
given frequency, it only takes a very short burst of low power RF to
reset on QSY, but it really needs to be done at 100W or less. This is no
problem with the barefoot K3 -- I can recall the tune setup with a
couple of dashes from the keyer. This technique would be disastrous
once the KPA500 is online, so I'm clearly going to need a way to
initially transmit at lower power after a band change to wake the tuner
up. I realize I could select the menu option to drop the amp offline
after every band change, but since I need to turn the amp off only with
one of several antennas, this is a lot of ergonomic overhead.

With the K3 and KPA500 integrated and talking via the AUXBUS will the
firmware keep the amp offline when the K3 is in TUNE mode? This would
be really useful for my particular setup, and for anyone who uses a
remote tuner. I've looked over the manual for the KPA500 and it says
nothing about the behavior in this case.

If the amp stays live in TUNE, perhaps a future revision of the firmware
could present a menu item to let the user choose whether or not the amp
will be enabled in TUNE mode.

73...
Randy, W8FN
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Guy, K2AV

Re: KPA500 with K3 in TUNE mode?

In keeping with Bob's final comment...

My dad, RIP, used to talk about cars with all the new features, and
proposed a new model to his Ford dealership cousin, that included
among a hilarous list, an automatic *ss wiper, and an automatic **rt
filter. The later would be engaged any time an odor appeared and had
to be strong enough to drive axle deep through a garbage dump, or
shred a skunk in the radiator fan, and not smell anything on the
inside. An automatic version of the former, alas, could not be
trusted, and was invoked with the only button on the dashboard, all
else being automatic, including a mind-reading radio, which would come
on with the door opening and tune to a station matching your mood, or
if in a funk, remain off.

He bought a new '54 Chevy (to spite his cousin), without a heater in
it, and liked it that way. Said if he wanted to be warm outside the
house, he'd wear a coat.

Good thing he's not still alive, a ham, and reading this reflector.
Eric would have to ban him for all the names he'd drape on certain of
the readership.

73, Guy.

On Wed, May 11, 2011 at 9:01 AM, Bob Naumann <[hidden email]> wrote:

>
> While automating this (disable PTT to the amp for the first transmission
> after a band change - just like Tokyo Hy-Power does) should be part of the
> eventual Elecraft tuner /amp implementation, and not just when in tune mode,
> I'm surprised that pressing the "OPER/STBY" button on the front panel of the
> KPA500 constitutes "a lot of ergonomic overhead"?
>
> I think of what was "normal" with something like a Drake C-line, MN2000
> tuner and L4B amplifier. Now, there's some ergonomic overhead!
>
> Times and perspectives certainly have changed.
>
> 73,
>
> Bob W5OV
>
>
> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of Randy Farmer
> Sent: Tuesday, May 10, 2011 9:49 PM
> To: [hidden email]
> Subject: [Elecraft] KPA500 with K3 in TUNE mode?
>
> I'm busily preparing for my new KPA500 and working out all the station
> interface details. One of my antennas uses an SGC SG-235 remote tuner,
> which will support the amp's 500W output but must be tuned at lower
> power. I currently just hold the K3's TUNE button to generate about 20W
> to tune the SG-235. Once the tuner has found and memorized a match at a
> given frequency, it only takes a very short burst of low power RF to
> reset on QSY, but it really needs to be done at 100W or less. This is no
> problem with the barefoot K3 -- I can recall the tune setup with a
> couple of dashes from the keyer. This technique would be disastrous
> once the KPA500 is online, so I'm clearly going to need a way to
> initially transmit at lower power after a band change to wake the tuner
> up. I realize I could select the menu option to drop the amp offline
> after every band change, but since I need to turn the amp off only with
> one of several antennas, this is a lot of ergonomic overhead.
>
> With the K3 and KPA500 integrated and talking via the AUXBUS will the
> firmware keep the amp offline when the K3 is in TUNE mode? This would
> be really useful for my particular setup, and for anyone who uses a
> remote tuner. I've looked over the manual for the KPA500 and it says
> nothing about the behavior in this case.
>
> If the amp stays live in TUNE, perhaps a future revision of the firmware
> could present a menu item to let the user choose whether or not the amp
> will be enabled in TUNE mode.
>
> 73...
> Randy, W8FN
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

ac0h

Re: KPA500 with K3 in TUNE mode?

I agree.

One of these days someone will build the ultimate automatic amateur
radio station. One where all you do is flip the big switch on a
Saturday morning then come back on Sunday evening to see how many DX or
contest contacts "you" made over the weekend.

Where is the fun in running an auto-pilot station like that?

On Wed, 11 May 2011 12:43:14 -0400
Guy Olinger K2AV <[hidden email]> wrote:

> Good thing he's not still alive, a ham, and reading this reflector.
> Eric would have to ban him for all the names he'd drape on certain of
> the readership.
>
> 73, Guy.

--
R. Kevin Stover
AC0H
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

w8fn

Re: KPA500 with K3 in TUNE mode?

In reply to this post by Phil Salas

I didn't realize the AUXBUS comms were one-way. Turning the TUNE level
down to a few Watts would work OK with the 235 and the KPA500 on-line.
Unfortunately, I have another antenna matched with a SG-230 that I want
to use as well. I don't know if the low level would be enough for the
230 or not. I'll do some experimenting to see what it takes.

It would be nice if an Amp Inhibit signal were available. Maybe some day.

Thanks for the advice.

73...
Randy, W8FN

> The AUXBUS provides one-way communication between the KPA500 and the K3
> (KPA500 to K3). So the KPA500 won't know that the K3 is in TUNE mode. The
> KPA500 has about 12-13 dB gain, so if the SG235 can take up to 100 watts
> without problems, you could set the TUNE mode to output no more than 5-watts
> for tuning. Unfortunately the K3 amp-enable output is always active whether
> in TUNE mode or normal operating mode (I understand this is hard-wired and
> so can't be changed in firmware).
>
> What would be nice is if the K3 would output a signal (Dig Out 0 or Dig Out
> 1?) that would feed the amp-inhibit input on the KPA500 (pin 11) when you
> press TUNE on the K3. Not sure if this is possible, but that would do the
> trick.
>
> Phil - AD5X

w8fn

Re: KPA500 with K3 in TUNE mode?

In reply to this post by Bob Naumann W5OV

Maybe I should have said "operator headspace overhead" instead. As I get
older, I seem to be taking more and more advantage of every opportunity
to screw up. Change bands, rate turns to crap, takes longer and longer
to look at the lights and realize the amp's not engaged. It's bound to
happen.

You're right about how times have changed. I remember way back in '65
when I got a Johnson T/R switch installed to replace the old plastic
DPDT knife switch in my Novice station. I thought I'd died and gone to
heaven. Remember the colored tape on the front panels of the C-lines,
TS-830s and L-4Bs to mark the settings for each band for fast QSY? Now
here I am bellyaching about having to push one stupid switch. This
high-tech stuff is WAY too addictive, but it sure is fun!

73...
Randy, W8FN

> While automating this (disable PTT to the amp for the first transmission
> after a band change - just like Tokyo Hy-Power does) should be part of the
> eventual Elecraft tuner /amp implementation, and not just when in tune mode,
> I'm surprised that pressing the "OPER/STBY" button on the front panel of the
> KPA500 constitutes "a lot of ergonomic overhead"?
>
> I think of what was "normal" with something like a Drake C-line, MN2000
> tuner and L4B amplifier. Now, there's some ergonomic overhead!
>
> Times and perspectives certainly have changed.

w8fn

Re: KPA500 with K3 in TUNE mode?

In reply to this post by N5GE

That's just what I'm going to do. With all of the brain power in the K
line I had just hoped that the system might do it for me. Looks like it
won't. It just seems to me that if you have a no-tune amplifier, the
TUNE function must logically be for tuning something other than the amp,
and whatever that is it probably doesn't need to be done at high power.

73...
Randy, W8FN

On 05/11/2011 00:06, [hidden email] wrote:
> Hello Randy,
>
> You should put the Amplifier in standby and let the tuner tune from the K3's
> Tune power. That applies to all amplifiers. It doesn't make any difference
> what brand of amplifier or what type of tuner you have you have.
>
> The safe way to tune a tuner before applying amplifier power is what I described
> above, no matter what it's final output will be.
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Nels Anderson

Re: KPA500 with K3 in TUNE mode?

In reply to this post by w8fn

I'm confused as to why the aux bus is referred to as being one way.

Just received KPA500 #32 yesterday and starting playing around with it.
When I change bands on the K3 the band automatically changes on the
KPA500 (as indicated by the display). When I use one of the band buttons
on the KPA500 to change bands, the same band change takes place on the
K3. To me that sounds like two way communications. Still more learning
to do to maximize ease of operation though :-)

73 Nels K1UR

On 5/13/2011 8:48 AM, Randy Farmer wrote:

> I didn't realize the AUXBUS comms were one-way. Turning the TUNE level
> down to a few Watts would work OK with the 235 and the KPA500 on-line.
> Unfortunately, I have another antenna matched with a SG-230 that I want
> to use as well. I don't know if the low level would be enough for the
> 230 or not. I'll do some experimenting to see what it takes.
>
> It would be nice if an Amp Inhibit signal were available. Maybe some day.
>
> Thanks for the advice.
>
> 73...
> Randy, W8FN
>> The AUXBUS provides one-way communication between the KPA500 and the K3
>> (KPA500 to K3). So the KPA500 won't know that the K3 is in TUNE mode. The
>> KPA500 has about 12-13 dB gain, so if the SG235 can take up to 100 watts
>> without problems, you could set the TUNE mode to output no more than 5-watts
>> for tuning. Unfortunately the K3 amp-enable output is always active whether
>> in TUNE mode or normal operating mode (I understand this is hard-wired and
>> so can't be changed in firmware).
>>
>> What would be nice is if the K3 would output a signal (Dig Out 0 or Dig Out
>> 1?) that would feed the amp-inhibit input on the KPA500 (pin 11) when you
>> press TUNE on the K3. Not sure if this is possible, but that would do the
>> trick.
>>
>> Phil - AD5X

Eric Swartz - WA6HHQ

Re: KPA500 with K3 in TUNE mode?

Administrator

In reply to this post by w8fn

There is a menu option for the KPA500 that automatically drops it into
standby on a new band change just for this purpose. (Normally defaulted
to OFF.)

Band data is sent from the K3 to the KPA500 via the binary band-data
lines, not the AUXBUS.

73, Eric WA6HHQ

On 5/13/2011 5:48 AM, Randy Farmer wrote: